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NIOSH Resolution of W. R. Grace 

Site Profile Finding 1

White Paper

National Institute for Occupational 

Safety and Health

August 28, 2019

Thomas P. Tomes 

Division of Compensation Analysis and Support 

Reviewed by:

Timothy D. Taulbee, Ph. D., CHP 

David Allen

Division of Compensation Analysis and Support

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 
White Paper NIOSH Resolution of W. R. Grace August 28, 2019

 Site Profile Finding 1

Page 2 of 8

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

FINDING 1

SC&A’s review of the W. R. Grace Technical Basis Document has the following summary for 

Finding 1 (SC&A 2013, p. 9): 

The accuracy and completeness of the recorded bioassay data have not previously been 

addressed by either DOE or NIOSH as part of a routine “verification and validation” (V&V) 

database review. SC&A performed a preliminary scan of the WRG DOE files for a small 

sampling of claimants and did not identify any outstanding issues. However, a broader and more 

detailed survey should be conducted that would determine if workers who should have been 

monitored because of job title (i.e., chemical operator, production-line operator, etc.) and/or 

location (i.e., production buildings, waste facilities, burial grounds, etc.) have recorded bioassay 

data for the corresponding periods when working in these areas. 

SC&A also added additional comments on this finding and concluded from a sampling of worker 

files for 1957 through 1970 “that a relatively small fraction of the workers were bioassayed, 

mostly for uranium by urinalysis.” SC&A also stated that a scan of the files indicates plutonium 

bioassays are not evident until after the operational period ended (1970) and concluded coworker 

models are needed (SC&A 2013, pp. 22-29). 

This finding was discussed by the Work Group on August 13, 2015. NIOSH reported that no 

uranium bioassay data are available until late 1964 and that the site profile provides uranium 

intakes for unmonitored workers. NIOSH also indicated that the site profile provides intakes 

from residual uranium contamination starting in 1971 (start of the residual contamination 

period). However, NIOSH also indicated a review was needed to determine: (1) whether or not 

the available uranium bioassay data is sufficient to assess intakes for the period of Burial 

Grounds remediation starting in 1991, and (2) whether or not the available plutonium bioassay is 

sufficient to reconstruction intakes of plutonium. 

This paper provides an overview of available internal dose monitoring data, followed by an 

assessment of adequacy of those records for reconstructing intakes of uranium and plutonium. 

BIOASSAY PROGRAM

This section is a summary of the bioassay data and other internal dose monitoring data that are 

available in claimant records. 

NIOSH reviewed the monitoring records of all W.R. Grace claims in the NIOSH OCAS Claims 

Tracking System (NOCTS). There were 270 claims in NOCTS as of May 3, 2019. The “DOE 

Response” files were reviewed and lists made of the data that are available. Of the 270 worker

files reviewed, 151 had employment in 1991 or later. The 151 files of workers employed 1991 or 

later were reviewed in detail as explained below. 
White Paper NIOSH Resolution of W. R. Grace August 28, 2019

Site Profile Finding 1

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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

Routine Uranium Urinalysis Program 1964 Through 1993

Claimant records indicate a robust uranium urinalysis program began in the fourth quarter of 

1964; no bioassay monitoring records are found prior to late 1964. Most workers have multiple 

uranium bioassay results reported in all years through 1993. The uranium bioassay results are 

reported in units of uranium dpm per liter. Claimant records indicate the routine monitoring 

program ended in late 1993, which coincides with a number of workers being laid off and with 

the completion of the plutonium facility decommissioning project. A uranium bioassay program 

was reinstituted in the latter part of 1997. 

Although the data in NOCTS indicates most workers have many uranium urinalysis data for all 

years worked for 1964 through 1993, some workers with certain job titles (administrative and 

office type workers) have less frequent or only limited bioassay data, and there are several claims 

with employment during the AWE operational years (1958 through 1970) that do not have any 

bioassay data in NOCTS even though their job titles indicate they would have been monitored. 

Some of those workers with no data in NOCTS had very brief employment periods. For those 

workers with no or incomplete uranium monitoring data, the NIOSH technical basis document 

(TBD) provides default intakes. Therefore, no additional assessment of the adequacy of uranium 

bioassay was done for 1958 through 1990. However, the TBD specifies bioassay data should be 

used for workers remediating the Burial Grounds starting in 1991. All claims for workers with 

work in the post 1990 period were reviewed. 

Of the 151 claims reviewed in NOCTS with employment after 1990, 136 of the claims have onsite work for all or part of 1991 through 1993. Of the 136 workers, 110 have routine uranium 

urinalyses during that period. The other 26 workers had no or only occasional uranium 

monitoring results in that period.

Routine Uranium Urinalysis Program 1997 to Present

There does not appear to have been a routine uranium urinalysis program from late 1993 until 

1997. Starting in the latter half of 1997, a number of workers were routinely monitored for 

exposure to uranium by urinalyses, with the results reported in units of micrograms per liter. Of 

the 151 claims reviewed in NOCTS with employment after 1990, 97 of the workers had on site 

work in late 1997 or later. Of the 97 workers, 43% (42 of 97) have routine uranium urinalyses

results in NOCTS from at least part of that period; the remaining 55 workers do not have in vitro 

data in the post 1997 period. The unmonitored workers includes some Operators and other job 

types who were included in the routine bioassay program that ended in 1993.

In Vivo Monitoring

Many workers have in vivo chest count results starting as early as 1970. The chest counts were 

performed by Helgeson Nuclear Services with a phoswich detector. The workers’ U-235 chest 

count results are reported to NIOSH on forms that list the date of examinations and U-235 results 

in micrograms. There are also individual examination reports from Helgeson that provide the 

U-235 result in micrograms and the two sigma uncertainty. Detection limits are not provided in 
White Paper NIOSH Resolution of W. R. Grace August 28, 2019

 Site Profile Finding 1

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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

the reports, but the NIOSH TBD reports a 120 microgram minimum detectable activity for U235 (ORAUT 2011). In addition to the Helgeson lung counter, NFS had special monitoring of 

some workers performed at other DOE facilities (AEC 1974; Author unknown 1988). 

NFS constructed a new in vivo counting system that became operational in September 1987. The 

system had four germanium detectors that were positioned over the subject’s lungs while seated 

in a semi-reclining position in a shielded facility. NOCTS records indicate 30 minute counts 

were performed. The facility was owned by NFS, but operated by Canberra. After the system 

became operational NFS reported a study of a few workers who had lung burdens measured with 

the Helgeson counter, and noted that measurements with the new germanium counter, and 

measurements of those workers at another site, indicate the Helgeson lung counter 

underestimated the amount of uranium-235 in the lungs (Author unknown 1988). 

After the NFS counter became operational in 1987, most workers in NOCTS have annual chest 

count reports up to the present. Reports include detection limits (minimum detectable activity) 

for radionuclides in the uranium, plutonium, and thorium series and cesium-137. Of the 151 

claims from NOCTS (with post 1990 employment) reviewed for this white paper, 141 have chest 

count results available in NOCTS; the other 10 workers have no chest count results in NOCTS. 

Of the 141 workers monitored, 121 of the workers were routinely monitored, and another 20 

were monitored during part of their employment. 

Other Internal Dose Monitoring Data

As described above the site had a robust uranium urinalysis program from 1964 through 1993. 

Starting with 1994, the NFS monitoring reports sent to NIOSH have annual worker intakes 

reported on the NRC Form 5 annual dose report. These intakes are provided for individual 

radionuclides in units of microcuries. The intakes were determined by NFS based on air 

sampling data, stay time information, and respiratory protection, as applicable (ORAUT 2017). 

NIOSH has not determined whether or not the intakes listed on Form 5 also included intakes 

derived from bioassay data, although it is logical to presume those intakes are included as well as 

intakes determined from air sampling data.

NOCTS has claims for 109 workers who worked at the site in 1994 or later. Of the 109 workers, 

90 of them have annual intakes reported in one or more years on NRC Form 5. The dose report 

includes annual intake by radionuclide in microcuries, intake mode, and inhalation solubility 

class. These data should be used to supplement dose reconstructions when bioassay data are not 

sufficient to quantify all intakes. 

A number of employees have enhanced routine in vitro monitoring from 1990 through 1993 that 

included routine uranium, thorium, and plutonium urine and fecal analyses. This enhanced 

monitoring coincided with the period of remediation of the plutonium facility. 

The site had an extensive air sampling program, as indicated by the large number of workers 

who had assigned intakes from air sampling data starting in 1994 on NRC annual dose reports 
White Paper NIOSH Resolution of W. R. Grace August 28, 2019

Site Profile Finding 1

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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

(other records available to NIOSH indicates an extensive air sampling program existed much 

earlier than that).

Additionally, some claims have DAC-hr exposure information that is useful to supplement the 

bioassay data. A number of the claims in NOCTS also have special monitoring data and 

assessments of intakes.

ADEQUACY OF URANIUM DATA

Finding 1 indicated NIOSH needs to assess adequacy of bioassay data for workers involved with 

remediation of the Burial Grounds starting in 1991. For this white paper, no effort was made to 

try to determine who was involved with Burial Ground remediation. This paper assessed all 151 

workers in NOCTS with post 1990 employment.

Based on the data reported to NIOSH, the most comprehensive internal dose monitoring data

available for the post 1990 era are the in vivo chest count data; these records include detection 

limits for U-235 that can be used to estimate total uranium. Of the 151 workers reviewed, 121 of 

them were routinely monitored on an annual frequency throughout their employment. 

Of the 30 workers who do not have routine annual chest counts in the post 1990 era, 20 of them 

have some chest count data available, but not for all years. The remaining 10 workers have no in 

vivo chest count measurements in NOCTS. 

Claims for all 30 workers with no, or only partial, annual chest counts were reviewed. Two of 

those claims appear to have incomplete responses in the DOE Response file because the files 

indicate the workers were likely monitored for intakes. NIOSH will review the two claims and 

follow-up with the site. Of the remaining 28 claims with limited in vivo data or no in vivo data, 

the descriptions of work for those individuals indicate they worked in jobs or in administrative

areas where elevated workplace airborne radioactivity is not likely. The job categories include: 

Secretary, Manager, Clerk/Typist, PC Specialist, Director, Contracts Administrator, Guard, 

Security, Material Control & Accountability, Administrative Assistant, Supervisor of Delivery, 

and Analyst (recent years), (NOTE: a few of those workers changed jobs and were apparently 

removed from the routine monitoring program; the job titles used in this review are those 

associated with the 1990s period). On-site environmental intakes are appropriate for these

unmonitored workers. Environmental intake rates were provided to the Work Group in a NIOSH 

white paper of July 22, 2019. It should be noted that only 10 claims have no in vivo data, while 

20 workers were monitored once or more, but not every year. Some workers had jobs titles that 

appears to have had some periods with potential exposure. For example, several security 

personnel are included in the 30 workers who were not routinely monitored in all years, but all of 

them have some monitoring data. 

Based on a review of all 151 claims in NOCTS with post 1991 site work, NIOSH concludes all 

the workers have either sufficient data to reconstruct intakes of uranium, or that environmental 

intakes are appropriate for the workers with unmonitored periods of employment. This 

conclusion is based solely on in vivo data. As described earlier in this paper, NIOSH has other 
White Paper NIOSH Resolution of W. R. Grace August 28, 2019

Site Profile Finding 1

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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

monitoring data for many workers that can be utilized, as appropriate, to estimate or bound 

intakes.

ADEQUACY OF PLUTONIUM DATA

NIOSH provided a white paper dated March 1, 2019, to the Work Group that contained 

coworker bioassay data for the period plutonium was produced at W. R. Grace, 1965 through 

1973. That paper also contained intakes based on air concentrations for workers who may have 

entered the facility during the idle period and for general areas of the facility. Table 1 of the 

March 1, 2019, paper provides a timeline of plutonium activities. It shows the site began 

characterization of the plutonium facilities in 1988, began decontamination and decommission 

(D&D) work in 1990, and completed plutonium D&D work in 1993 (with the exception of an

underground contaminated area inside a containment). 

As discussed previously in this white paper, the site enhanced their internal dose monitoring 

program at a time that coincided with characterization of the plutonium facilities. A new in vivo 

facility became operational in late 1987. Additionally, starting in 1990 enhanced worker in vitro 

monitoring is found for a number of workers that include routine urine and fecal samples for 

uranium, thorium, and plutonium.

This paper previously discussed the in vivo monitoring program and concluded all workers with 

employment post 1990, and who have claims in NOCTS, have sufficient in vivo data to assess 

intakes for uranium, or that environmental intakes are appropriate (as noted earlier there are two 

claims for workers with post 1990 work in which the DOE Response files appear to be missing 

internal dose monitoring data). The in vivo reports also provide values and detection limits, 

including U-235, Pu-239 and Am-241. These data are sufficient to estimate or bound intakes of 

plutonium and uranium. The Adequacy of Uranium Data section discussed the 151 claims with 

employment post 1990, but did not evaluate sufficiency of data prior to 1991. There are an 

additional 12 claims in NOCTS for workers who worked some or all of 1988 through 1990. The 

data from those 12 claims were reviewed.

Of the 12 claims, 10 have routine in vivo examinations. One of the claims has an incomplete 

DOE Response file that NIOSH will review and follow-up with the site. The other claim with no 

routine in vivo examinations in that period was reviewed for information on exposure potential. 

During that period that worker performed duties in two specified facilities, neither of which are 

plutonium facilities (the worker was routinely monitored for uranium by urinalysis). 

NIOSH concludes, that with the exception of three workers whose DOE Response files are 

incomplete, the in vivo data are sufficient to estimate or bound intakes of plutonium from 1988 

on. Except where noted, this review made no attempt to actually determine who was potentially 

exposed to plutonium. 
White Paper NIOSH Resolution of W. R. Grace August 28, 2019

 Site Profile Finding 1

Page 7 of 8

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

CONCLUSION

NIOSH has reviewed all claims in NOCTS to determine whether or not worker monitoring data 

are sufficient to reconstruct uranium intakes in the post 1990 period. NIOSH concludes that all 

workers who should have been monitored for intakes of uranium have either in vivo monitoring 

data, in vitro monitoring data, or both. Two claims were identified for workers whose NOCTS 

files indicate they were likely monitored for uranium, but the response file from the site appears 

to be missing the data. NIOSH will follow-up with the site for those two claims.

NIOSH has also reviewed all claims in NOCTS with employment post 1987 to determine if there 

are adequate monitoring data in the period of plutonium decontamination and decommissioning 

work. Two claims from the post 1990 era that are discussed in the above paragraph, and one 

claim in the 1988 through 1990 period, have apparent incomplete data responses from the site 

that NIOSH will review and follow-up with the site. NIOSH concludes that all workers who 

should have been monitored for plutonium were routinely monitored by annual chest counts. The 

review of available data in NOCTS also indicates the site had enhanced in vitro monitoring for 

multiple radionuclides for a number of workers during the plutonium D&D period. 
White Paper NIOSH Resolution of W. R. Grace August 28, 2019

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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution. 

REFERENCES

AEC (United States Atomic Energy Commission), 1974, correspondence between the United 

States Atomic Energy Commission, Oak Ridge Operations, Oak Ridge, Tennessee, and Nuclear 

Fuel Services, Erwin, Tennessee, April 9 through May 1. [SRDB Ref. ID: 95146] 

Author, unknown 1988, In Vivo Cross Comparison Study, Erwin, Tennessee, September 21. 

[SRDB Ref ID: 41262, pp. 25-44] 

ORAUT (Oak Ridge Associated Universities Team), 2011, Technical Basis Document: An 

Exposure Matrix for W.R. Grace and Company in Erwin, Tennessee, ORAUT-TKBS-0043, Rev 

02, September 16. [SRDB Ref. ID: 101734] 

ORAUT (Oak Ridge Associated Universities Team), 2017, Correspondence with Nuclear Fuel 

Services, February 23. [SRDB Ref ID: 165852] 

SC&A (S. Cohen & Associates), 2013, Review of the NIOSH Site Profile for the W.R. Grace and 

Company in Erwin, Tennessee, Document No. SCA-TR-SP2013-0041, Vienna, Virginia, 

January 16. [SRDB Ref ID: 166040]